Over time, demands on modern inventory management systems have increased. Those demands include the need for more complex and diverse inventories, the need to sort and combine smaller quantities of inventory in support of order fulfillment, and more efficient use of time, space, equipment, and manpower. Accordingly, the inefficient utilization of system resources is increasingly unacceptable. Inventory management systems unable to meet these increasing demands suffer from lower system throughput, unfinished or delayed tasks, and unacceptable response times.